Sign holder



FIG. 1 is a perspective view;

FIG. 2 is a left side view with the opposite side being a mirror image;

FIG. 3 is a back view;

FIG. 4 is a top view;

FIG. 5 is a bottom view; and,

FIG. 6 is a front view. 

The ornamental design for a sign holder, as shown and described. 